Woven fabric



Ocf- 24, 1950 Y D. FlNLAYsoN Erm. 2,526,738

wovEN FABRIC Filed Sept. l0, 1946 Y Patented Oct. 24, l 1950 HarryCraWsha-W,Y London, England, yassignors to Celanese Corporation `ofAmerica, a corporation of Delaware Applicationseptember 10, 1946, SerialNo. 695,870 In Great Britain September 12, 1945 12 claims. (C1. 13a-4205.This invention relates to woven fabrics and is particularly concernedwith fabrics of the class suitable for use as conveyor belts and powertransmission belts, which are required to have exceptional strength in awarpwise direction.

In fabrics of this kind, while the main requirement is that the fabricshould have a high tensile strength in a warpwise direction, asubstantial degree of strength is required also in the weftwisedirection, not only to prevent splitting of the fabric along the warpbut also in order that, where two ends of the fabric are joinedtogether, the joint itself may have a warpwise strength commensuratewith that of the fabric. It has been found however that, apparently byreason ofinterference between the warp yarns. and the substantial`proportion of weft yarns necessary to give the requisite weft strength,the warp strength of the fabric is aptto fall far short of the aggregatestrength of all the individual warps therein. This failure to realise inthe fabric the maximum strength of theA warps is particularly marked ifthe warp consists of materials, and especially continuous lamentmaterials, that have been stretched-.while in Va softened condition atsome stage in their manufacture so as to increase their tensilestrength. .It has now been found that a particular kind of braid, namelyone in which the major proportionof the weight of the constituent yarnsconsists of yarns running substantially parallel to the axis of thebraid and not across or helically round it, is apparently less liablethan 1an' ordinary heavy yarn to loss of tensile strength because ofinterference by other yarns. When such braids are used as warps inheavyfabrics',l

the aggregate strength of thewarps is more closely realised as the warpstrength ofthey fabric than when other warps of equal tensile strengthare used.

The present invention, therefore, includes a woven fabric, suitable foruse in conveyor or power transmission belts, having a warp consisting ofor comprising braids in each of which the major proportion of the weightof the constituent yarns, for example 80 to 90% or more, consists ofyarns running substantially parallel to the axis of the braid. In orderthat the principal yarns of the braid may lieparallel to the Aaxisthereof, it is necessary that the braidshould'comprise, in additionv tosuch principal yarns, auxiliary or binder yarns crossing andinterlacin'g with the principal yarns and therefore not lying parallelto the braid. The braid may comprise a tubular ,element or sheath, withthe binder yarns running helically round it and may contain a core ofparallel yarns co-operating with the principal yarns but not interlacedwith the binder yarns. Braids of this kind can be made on braidingmachines or can be woven in smallware looms by suitable sheddingarrangements. Where a braiding machine is employed, binder yarns may bearranged to run helically in both directions round the braid so that thebinder yarns cross one another at intervals. Where a loom is employedfor weaving the braid the binder yarn, serving as weft in the loom, willrun helically round the braid always in the same direction at all partsof the length of the braid.

The braids employed in warps in the fabric of the presentv invention maybe woven into the fabric with wefts of similar construction and of thesame or lighterweight. Prefer-ably, however, where a braid is used asthe weft a fiat braid is employed. When such a iiat braid is employed inthe weft it is of less importance that the bulk of the constituentyarnsshould run parallel to the aXsthereof than in the case of the braidemployed as warp. Thus a flattened tube may be employed in which all theyarns run helically round the braid at an angle to the axis thereof, theatness of the braid minimising the interference between it and thebraids used in the warp and thus enabling the aggregate strength of thewarp braids to be even more closely realised as the warp strength of thefabric. Or again, singles yarns, or composite yarns whose components aredoubled or cabled together but not braided, may be employed as the weft.

The fabric according to the invention is of particular advantage inbelts in which a fabric foundation, generally in the form of severallayers of fabric secured together by means of rubber or other flexibleadhesive, is provided with a covering of rubber or like iiexiblematerial to give a smooth surface of the desired texture andconsistency. Oneparticularly important application of the invention isfor conveyor belts as used underground in coal mines. Belts forthispurpose work under very severe conditions giving rise to frequentbreakage, and the realization of the maximum tensile strength of thefabric is of particular value in reducing such breakage and increasingthe life of the belt. When intended for use as a belting, thel fabricaccording to the invention may bemade as described land claimed in U. S.Application S. Number 607,301, filed on July 27,1945, now Patent Number2,494,646, issued Jan. 1'7, 1950', i. e. with a weft inserted at shortintervals in the fabric that the tear-out strength of the joint betweentwo ends of the fabric.

The invention is also of particular advantage where the yarns employedin the fabric, Vand particularly in the Warp braids, are of high tensilestrength and are made by stretching filamentsof.

cellulose acetate or other organic derivative of cellulose in thepresence of Wet steam or other softening agent adapted to facilitatestretching. Where the filaments that are stretched are of celluloseacetate or other cellulose ester, they are preferably saponied afterbeing stretched. Warps which are of high tensile strength because theyor their constituent yarns have been stretched in this way areparticularly liable to diminution of their tensile strength because ofinterference by the weft with which they have been Woven, and thepresent invention is of particular advantage since it reduces thistendency. The invention may, however, be applied also to fabricscontaining other kinds of yarns, egg. to fabrics in which the warp orweft or both are of linen or cotton, or artificial staple libres made bycutting continuous laments into suitable lengths.

The fabrics according to the present invention may be classifiedgenerally as heavy fabrics that cover a substantial range of weights.Thus for example, they may be woven from braids of a Weight of say45,000 denier each, spaced at say. ends per inch giving a fabric of theorder of 4 lbs. per square yard in weight, or from braids of about 9000denier or less at a spacing of 18 ends per inch, giving a fabric ofabout 1.5 lbs. per square yard or less. Where flat braids are used inthe weft they may be of similar weight or rather lighter Weight than theWarp braids though much more widely spaced, e. g. at from 2 to 5 picksper inch.

The following are given as examples of fabrics in accordance with theinvention.

Eixample 1 l The fabric is made with a Warp of braids each consisting ofcontinuous filament yarns made by stretching continuous laments ofcellulose acetate in the presence of wet steam to ten times theiroriginal length and then saponifying the stretched yarn. Each braidcomprises eight longitudinal sheath yarns and three core yarns all of1100 denier, the sheath yarns being braided with four binder threadseach of 275 denier. Of the binder threads two run in one direction andtwo in the other direction round the braid, the total number of laps perinch of binder threads round the braid being about seven. These braidsare woven at 18 ends per inch With'a. at braid made by helicallybraiding together 48 yarns, each of 275 denier, 24 of -the yarns runningin one direction and 24 in the other round the braid and giving a braidof about 51g of an inch wide. The weft braid is inserted at a density of3 picks per inch. The resulting fabric is about 2.2 lbs. per square yardin weight.

Emample 2 inch with a weft braid as described in Example l woven at 3picks per inch, the resulting fabric bee ing about 3.6 lbs. per squareyard in Weight.

Example 3 A braid is formed by weaving 22 heavy warp yarns, made ofcontinuous filaments like those of Examples 1 and 2, and each of 2750denier, with a single weft of 275 denier, the mode of weaving beingYsuch that I of the warp yarns are not interlaced with the weft but forma core surrounded by a tube formed by the interlacing of the remaining15 yarns with the weft. This braid is woven as the warp at nine ends perinch with a flat braid as described in Examples 1 and 2, woven at 21/2picks per inch. The resulting fabric is of the order of 5 lbs. persquare yard in Weight.

Emample 4 The warp braids of Example 2 are woven at 12 ends per inchwith a continuous filament doubled yarn of 4500 denier employed as theweft and woven at 4 picks per inch.

Example 5 The fabric is of the kind described in U. S. Application S.Number 607,301 led July 27, 1945, and contains a heavy weft occurring atintervals along the fabric. A braid similar to that of Example 1, buthaving six sheath yarns and two core yarns each formed by doublingtogether three 550 denier yarns, is employed in the warp at a spacing ofabout 14 ends per inch. In the weft, a 3300 denier continuous filamentyarn is employed at an average spacing of 15 picks per inch, 5 picks inseparate sheds alternating'with 5 picks all in the same shed so as togive a heavy weft occurring at about every z/3".

The fabrics described in the preceding eX- amples, and the braidsemployed in the construction thereof, are shown in the accompanyingdrawings in which:

Figure 1 is an enlarged diagrammatic view of a warp braid in which aplurality of binder yarns are employed.

Figure`2 is a similar view of a Woven warp braid in which a singlebinder yarn is employed.

Figure 3 is a similar view of a flat braid suitable for use in the weftof the fabric.

Figure 4 is a diagrammatic view of a fabric of the kind described inExamples l and 2, and

Figures 5, 6 and 7 are similar views of the fabrics described inExamples 3 to 5, respectively.

In Figure l the principal sheath yarns are indicated at 8 and thecoreyarns at 9. The binder yarns I0 and II pass helicallyround the braidin one direction and the binder yarns I2 and I3 in the other direction,the yarns I0-I3 being interlaced with the sheath yarns 8 so as to. forma tube enclosing the core yarns 9, and crossing each other.

The braid shown in Figure 2 also comprises sheath yarns 8 and core yarns9, but in this case there is only a single binder yarn I5 runninghelically round the braid and interlaced with the sheath yarns 8 to forma, woven tube enclosing the core yarns 9.

The braid shown in Figure 3 is a flat tubular braid, containing no coreyarns, in which the yarns I 6 al1 pass helically round the braid, equalnumbers in both directions, and are interlaced with each other..

- Figure 4 showsl a plain woven fabric inwhich, as described in Examples1 and 2, the warps I'I are in the form of braids of the kind shown inl?.

'Figure l, while the vvefts I8 kind shown in Figure 3.

ments are braids of the In Figure 5, asimilar weft yarn I8 is employed,but, as .described in Example 3, the warps I9 are braids of the kinddescribed with reference to Figure 2.

. -InvFigures 6 and '7 the warps are againv in the formA of braids ofthe kind shown in Figure l, while the wefts, as described in Examples 4and 5, are simply doubled yarns of continuous fila- The wefts in Figure6 are'wovenwith the warp at uniform intervals in a plain weave, asdescribed in Example l but in Figure 7, while vmost of the wefts 2D aresingle picks of yarn,

certain wefts 2I, occurring at regular intervals along the length of.the fabric, consist of several picks ofthe same yarn, as described inExample 5.

Having described our invention, what we desire to. secure by LettersPatent is:

1. .'Abelting fabric of woven construction and having a Warp comprisingbraids consisting of a tubular sheath of textile yarns and a core ofparallel textile yarns enclosed therein, the major proportion by Weightof said sheath consisting of textile yarns running substantiallyparallel to the axis of said sheath and theminor proportion consistingof textile binder yarn running helically around said sheath and crossingand interlacing with the yarns of said major proportion but not with theyarns of said core.

2. A belting fabric of 'Woven construction and having` a warp comprisingbraids each consisting of a Woven tubular sheath of textile yarns and acore of parallel textile yarns enclosed therein, the major proportion byWeight of said sheath consisting of textile yarns ruiming substantiallyparallel to the axis thereof and the minor proportion consisting of asingle textile binder yarn runningv helically rOundsaid sheath andinterlacing with the yarns` of said major proportion kbut not with theyarns of said core.

3. A belting fabric of woven construction and having a warp comprisingbraids each consisting of a tubular sheath of textile yarns and a coreof parallel textile yarns enclosed therein, the major proportion byweight of said sheath consisting of textile yarns running substantiallyparallel to the axis of said sheath and the minor proportion consistingof a plurality of textile binder yarns running helically in bothdirections round said sheath so as to cross one another at intervals,and crossing and interlacing with the yarns of said major proportion butnot with the yarns of said core.

4. A belting fabric of woven construction, comprising a flat textilebraid as a weft and having a warp comprising braids consisting of atubular sheath of textile yarns and a core of parallel textile yarnsenclosed therein, the major proportion by Weight of said sheathconsisting of textile yarns running substantially parallel to the axisof said sheath and the minor proportion consisting of textile binderyarn running helically around said sheath and crossing and interlacingwith the yarns of said major proportion but not with the yarns of saidcore.

5. A belting fabric of woven construction and having a warp comprisingbraids of textile material in each of which the major proportion byWeight of the constituent yarns consist of yarns running substantiallyparallel to the axis of the braid and the minor proportion comprisesbinder yarn running helically around said sheath and crossing andinterlacing With yarns of said major proportion, said Warp being wovenwith textile .wefts 'at intervals .amongst which, distributedy alongthe' length of the fabric, a weft is inserted ofV several times the.weight of the Wefts elsewhere in the fabric.

6. A belting fabric of woven construction and having a warp comprisingbraids consisting of a tubular sheath of textile yarns and a core ofrparallel textile yarns enclosed therein, the major proportion by weightof said sheath consisting of textile yarns running substantiallyparallel to the axis of said sheath and the minor proportion consistingof textile binder yarns-running helically around said sheath andcrossing and inter- -lacing, withthe yarns of said major proportion butnot with the yarns of said core, said warp being Woven with textileWefts at intervals amongst which, distributed along the length of thefabric, a weft is inserted of several times the weight of the weftselsewhere in the fabric.

7. A belting fabric of woven construction and having a warp comprisingbraids made of yarns of continuous filaments of cellulose acetate orother organic ester of cellulose that have been stretched in thepresence of a softening 'agent adapted to facilitate stretching and thathave been saponiiied after stretching so as to increase their tensilestrength, each of said braids consisting of a woven tubular sheath and acore of parallel yarns enclosed therein, the major proportion by weightof said sheath consisting of yarns running substantially parallel withthe axis thereof and the minor proportion consisting of a single binderyarn running helically round said sheath and interlacing With the yarnsofl said major proportion. but not With'the yarns of said core.

8. A belting fabric of. woven construction and having a Warp comprisingbraids made of yarns of continuous filaments of cellulose acetate orother organic ester of cellulose that have been stretched in thepresence of a softening agent adapted to facilitate stretching and thathave been saponied after stretching so as to increase their tensilestrength, each of said braids consisting of a tubular sheath and a coreof parallel yarns intervals and interlacing with the yarns of said majorproportion but not with the yarns of said core. f

9. A belting fabric of woven construction having a weight of from 1.5 to4 lb./sq. yd., said fabric comprising a flat textile braid as weft andhaving a warp comprising braids mad-e of yarns of continuous filamentsof cellulose acetate or other organic ester of cellulose that have beenstretched in the presence of a softening agent adapted to facilitatestretching and that have been saponied after stretching so as toincrease their tensile strength, each of said braids consisting of aWoven tubular sheath and a core of parallel yarns enclosed therein, themajor proportion by Weight of said sheath consisting of yarns runningsubstantially parallel With the axis thereof and the minor proportionconsisting of a single binder yarn running helically round said sheathand interlacing with the yarns of said major proportion but not with theyarns of said core.

10. A belting fabric of woven construction having a weight of 4from 1.5to 4 lb./sq. yd., said fabric comprising a flat textile braid as weftand having a warp comprising braids made of yarns of continuous lament'sof cellulose acetate or other organic ester of cellulose that have beenstretched in the presence of a softening agent 'adapted to facilitatestretching and that have been saponied after stretching so as toincrease their tensile strength, each of said braids consisting of atubular sheath and a core of parallel yarns enclosed therein, the majorproportion by weight of said sheath consisting of yarns runningsubstantially parallel to the axis thereof and the minor proportionconsisting of a plurality of binder yarns running helically in bothdirections round said sheath so as to cross one another at intervals andinterlacing with the yarns of said major proportion but not with theyarns of said core.

11. A belting fabric of woven construction having a Weight of from 1.5to 4 lb./sq. yd. and having a warp comprising braids made of yarns ofcontinuous filaments of cellulose acetate or other organic ester ofcellulose that have been stretched in the preence of a softening agentadapted to facilitate stretching and that have been saponifled afterstretching so as to increase their tensile strength, each of said braidsconsisting of a woven tubular sheath and a core of parallel yarnsenclosed therein, the major proportion by weight of said sheathconsisting of yarns running substantially parallel with the axis thereofand the minor proportion consisting of a single binder yarn runninghelically round said sheath and interlacing with the yarns of said majorproportion but not with the yarns of said core, said warp being wovenwith textile wefts at intervals amongst which, along the length of thefabric, a weft is inserted of several times the weight of the weftselsewhere in the fabric.

12. A belting fabric of Woven construction having a weight of from 1.5to 4 lb./sq. yd. and having a warp comprising braids made of yarns'ofcontinuous filaments of cellulose acetate or other organic ester ofcellulose that have been stretched in the presence of a softening agentadapted `to facilitate stretching and that have been saponified afterstretching so as to increase their tensile strength, each of said braidsconsisting. of a tubular sheath and a core of parallel yarns enclosedtherein, the major proportion by weight of said sheath consisting ofyarns running substantially parallel to the axis thereof and the minorproportion consisting of a plurality of binder yarns running helicallyin both directions round said sheath so as to cross one another atintervals and interlacing with the yarns of said major proportion butnot with the yarns of said core, said warp being woven with textilewefts at intervals amongst which, along the length of the fabric, a weftis inserted of several times the weight of the wefts elsewhere in thefabric.

DONALD FINLAYSON.Vv HARRY CRAWSHAW.

REFERENCES CITED The following references are of record the file of thispatent:

UNITED STATES PATENTS Number Name Date 40,379 Darker, Jr Oct. 20, 1863905,946 Stevenson Dec. 8, 1908 1,640,946 Lloyd Aug. 30, 1927` 2,096,592Petersen Oct. 19, 1937 2,217,826 Van Laer Oct. 15, 1940 FOREIGN PATENTSNumber Country Date 48,527 Austria Feb. 1, 1911 333,279 Great BritainAug. 8, 1930

